1. Field of the Invention
This invention relates to a data storage system. More specifically, the invention relates to a data storage system including an array of storage devices and providing multiple-faults protection.
2. Description of the Prior Art
In recent years, the speed and efficiency of computers are continuously raised and the capacities of storage systems are highly increased. Besides capacity and performance, reliability of large storage systems is also extremely important. To achieve better reliability, the abilities of error detection and error correction must be improved in large storage systems.
An array of storage devices is usually used for providing a larger data capacity than one single storage device. A technique named “redundancy” is frequently applied in arrays of storage devices. Redundancy means adding additional storage devices to store information about data in the original storage devices. Once the storage devices for storing data are failed, the data storage system can recover the data in the failed storage devices according to the redundancy information.
In actual applications, an array of storage devices may include a plurality of disks. Existing redundant arrays of independent disks (RAID) can be classified into the following categories: RAID 0, RAID 1, RAID 10, RAID 0+1, RAID 2, RAID 3, RAID 53, RAID 4, RAID 5 and RAID 6.
However, conventional RAIDs in prior arts can not provide sufficient protection for data or can only provide protection for data with a large amount of additional disk drives. RAID0 doesn't provide any redundancy. RAID1 provides single-fault protection by providing duplicate disk drives for each of the disk drives in the RAID 0 array. RAID 2, RAID3, RAID 4, and RAID 5 can also only provide single-fault protection, and once more than one disk drive is failed, the failed disk drives cannot be recovered. RAID 6 needs two additional disk drives for recovering two failed disk drives and once more than two disk drives are failed simultaneously, the failed disk drives can not be recovered.
The main purpose of this invention is providing a data storage system including an array of storage devices and providing multiple-faults protection. More particularly, once up to K storage devices in the array of storage devices are failed, the data storage system recovers the failed storage devices based on K sets of previously provided parameters, which are generated based on a generator polynomial. Especially, K can be a natural number larger than two. Accordingly, this invention provides a data storage system having multiple-faults protections and the data storage system can tolerate more failed storage devices than prior arts.